If you stick some clean reactive metal, like magnesium, into an aqueous solution of hydrochloric acid... Hey presto! Bubbles of hydrogen gas...

What makes a chemical reaction spontaneous? If I add hydrochloric acid (HCl (aq) ) to metallic magnesium (Mg (s) ), bubbles of hydrogen gas...

What is entropy? What is meant by a chemical system having low entropy or high entropy? What is the relationship between disorder, energy ...